Apparatus and method for transmitting an electrical signal in an implantable medical device

Abstract

A method and device for transmitting a signal in an implantable medical device that includes a control unit and a first electrode and a second electrode positioned along a lead body. A connector block is positioned along an upper portion of a housing portion of the control unit, and a connector is positioned at a proximal portion of the lead body and is insertable within the connector block. A third electrode having a conductive element is positioned along the control unit in close proximity adjacent to the connector. The control unit transmits a signal between the first electrode and the second electrode and determines an alternate transmission path of the signal between the third electrode and one or both of the first electrode and the second electrode in response to the signal not being effectively transmitted between the first electrode and the second electrode.

1. An implantable medical device, comprising:
 an elongated lead body extending from a proximal portion to a distal portion; 
 a first electrode and a second electrode positioned along the lead body; 
 a housing having an upper portion; 
 a control unit having a housing portion housing electrical components of the implantable medical device and a connector block positioned along an upper portion of the housing, the control unit transmitting a signal between the first electrode and the second electrode; 
 a connector positioned at the proximal portion of the lead body and insertable within the connector block to electrically couple the first electrode and the second electrode and the electrical components; and 
 a third electrode having a conductive element positioned along the control unit in close proximity adjacent to the connector, wherein the control unit determines an alternate transmission path of the signal between the third electrode and one or both of the first electrode and the second electrode in response to the signal not being effectively transmitted between the first electrode and the second electrode as evidence by a sub-threshold amplitude of said signal compared to a predetermined minimum signal threshold value. 
 
   
   
     2. The implantable medical device of  claim 1 , wherein the third electrode is positioned along the housing. 
   
   
     3. The implantable medical device of  claim 1 , wherein the third electrode is positioned along the connector block. 
   
   
     4. The implantable medical device of  claim 1 , wherein the connector block extends from a back portion to a front portion and the upper portion of the housing extends outward from the front portion of the connector block, and wherein the third electrode is positioned along the outward extending upper portion of the housing. 
   
   
     5. The implantable medical device of  claim 4 , further comprising an opening formed along the outward extending upper portion, wherein the conductive element is positioned within the opening. 
   
   
     6. The implantable medical device of  claim 2 , wherein the conductive element is embedded within the housing. 
   
   
     7. The implantable medical device of  claim 3 , wherein the conductive element is embedded within the connector block. 
   
   
     8. The implantable medical device of  claim 1 , wherein the connector block extends from a back portion to a front portion and the third electrode is positioned along the front portion of the connector block. 
   
   
     9. The implantable medical device of  claim 8 , further comprising an opening formed along the front portion, wherein the conductor element is positioned within the opening. 
   
   
     10. The implantable medical device of  claim 1 , further comprising:
 a microprocessor determining whether a signal is effectively transmitted between the first electrode and the second electrode; and 
 a switch matrix switching transmission of the signal to an alternate transmission path between the third electrode and one or both of the first electrode and the second electrode in response to the signal not being effectively transmitted. 
 
   
   
     11. The implantable medical device of  claim 10 , wherein the alternate transmission path is in one of a monophasic and a biphasic mode. 
   
   
     12. An implantable medical device according to  claim 1 , wherein the signal comprises one of a high-energy cardiac defibrillation signal and a low-voltage cardiac pacing signal. 
   
   
     13. A method of transmitting a signal in an implantable medical device to deliver an intended therapy for stimulating a patient's heart, comprising the steps of:
 transmitting the signal between a first electrode and a second electrode; 
 determining whether the intended therapy is successful; 
 in the event that that the intended therapy was not successful, then determining an alternate transmission path between a third electrode positioned in close proximity adjacent to a connector of the implantable medical device and one or both of the first electrode and the second electrode; and 
 transmitting the signal along the alternate transmission path. 
 
   
   
     14. The method of  claim 13 , wherein the signal is transmitted along the alternate transmission path in one of a monophasic mode and a biphasic mode. 
   
   
     15. The method of  claim 13 , wherein the step of determining the alternate transmission path comprises determining which of the first electrode and the second electrode are in sufficient contact with the patient's heart. 
   
   
     16. The method of  claim 15 , wherein the alternate transmission path is between the third electrode and the first electrode in response to the first electrode being in sufficient contact. 
   
   
     17. The method of  claim 15 , wherein the alternate transmission path is between the third electrode and the second electrode in response to the second electrode being in sufficient contact. 
   
   
     18. The method of  claim 15 , wherein the alternate transmission path is between the third electrode and both the first electrode and the second electrode in response to one of the first electrode being in sufficient contact and and the second electrode not being in sufficient contact, the second electrode being in sufficient contact and the first electrode not being in sufficient contact, and both the first electrode and the second electrode not being in sufficient contact. 
   
   
     19. The method of  claim 13 , wherein in response to determining the therapy is not successful, the alternate transmission path is determined to be between the third electrode and one of the first electrode, the second electrode and both the first electrode and the second electrode. 
   
   
     20. A method according to  claim 13 , wherein the therapy comprises one of a high-energy defibrillation therapy and a low-energy cardiac pacing therapy.